Just a quick question, are you planning on adding a way to add or decline challenges in the future? It may not be an issue now, but I can foresee a lot of people challenging people higher up on the ladder.. maybe perhaps more than they can/want to play?

Umm.... it's been almost 5 years. Has this been implemented and I just can't see it?

I had my status set to RED and got a challenge anyway which now gives me a notification that I can't clear in Steam (unless I turn off ALL Frozen Synapse notifications which I'd prefer not to do for games I do want).

This is annoying because if you want to play a balanced random map with your mate you need to challenge him more times until you find a nice map.
The devs answer is "use Advance Setup". Well this is not a welcome solution for many people because they don't like the idea of being able to modify the map (is like a potential cheating in their mind even they have no such intention). But devs never understood this.

The superficial devs solution to decline a game is "don't take first turn" and "hide it". So when you send a challenge, if your opponent don't
want to take first turn then you lost time by taking your first turn. You can't communicate with your opponent unless he is online.
Many times I had to send a private message to my opponent on Steam/forum to find out if he likes or not that map. And vice-versa.

Also you can't surrender neither. Another annoying thing. For sample you know that your sniper has no time to reach a bidden zone in Charge/Secure mode.

I hate to agree with Wonderhero as he beats me with impunity every time. I had to take some time off just to heal the mental wounds he caused.

Yet, I agree here, too. I hated myself to open three games (as far as I remember) with RADR, a really cool guy, just to ditch them as not one was balanced. Happened with Wonderhero, too. If both players are present at least they can agree to hide that game. Sadly the game has no way to leave a message to the missing party, so if both are not present, there is a high chance the other player will waste time to think the first turn over.